I was looking at a YouTube video earlier today and noticed a product called Sugru that they were using for several different applications. www.Sugru.com
It appears that it would be an excellent option for someone that is modifying a rifle stock and that will be using a truck liner products to paint the stock. This is a material that you could add a custom form fitted pistol grip before applying the truck liner material. Just wondering if anyone has seen or used this material before.
"Kill Em With Air"
This material looks as if it would be very useful in some situations. BUT, it stays flexible: http://sugru.com/about so probably is not good as part of a hand-grip.
Note this is a product in development. For example, it has a limited shelf life--up to 18 months if refrigerated--and they are working on improving that. This looks to me like something to keep an eye on as its development continues. Thanks for bringing it to our attention.